Communication device for mobile body, communication system for mobile body, and automatic time correction method featuring communication device for mobile body

ABSTRACT

The base station, which is installed in an aircraft and is capable of communicating with a terminal, comprises a wireless communication component that can be connected to the terminal, and a controller that controls the wireless communication component. The controller acquires regional information indicating at least the destination of the aircraft, determines time zone information corresponding to regional information, produces a time correction instruction according to the time zone information, and transmits the time correction instruction through the wireless communication component to the terminal.

PRIORITY

This application claims priority to Japanese Patent Applications No.2013-079225 filed on Apr. 5, 2013 and No. 2014-006955 filed on Jan. 17,2014. The entire disclosure of Japanese Patent Applications No.2013-079225 and No. 2014-006955 is hereby incorporated herein byreference.

BACKGROUND

1. Technical Field

The present disclosure relates to technology for correcting timeinformation in a terminal located in a mobile body, on the basis ofinformation from a base station located in the mobile body.

2. Background Art

There has been known a technique for automatically revising the clocktime of a terminal to a time based on the standard time of the regionwhere the terminal is used, by making use of position information fromGPS or the like. This technique is disclosed by, for example, JapaneseLaid-Open Patent Application 2006-029960, and the following non-patentliteratures.

-   Non-Patent Literature 1: 3GPP TS22.042 V11.0.0, “Network Identity    and Time Zone (NITZ); Service description; Stage 1 (Release 11),”    November 2012, and-   Non-Patent Literature 2: 3GPP TS24.008 V12.1.0, “Mobile radio    interface Layer 3 specification; Core network protocols; Stage 3    (Release 12),” March 2013

SUMMARY

This disclosure provides a communication device, a communication system,and an automatic time correction method that are effective at correctingthe time information of a terminal used in a mobile body that is a meansof transportation.

According to a first aspect of this disclosure, a communication deviceis provided in a mobile body which is a means of transportation, and iscapable of communicating with another communication device. Thecommunication device comprises a communication component that can beconnected to the other communication device, and a controller thatcontrols the communication component. The controller acquires regionalinformation indicating at least the destination of the mobile body,determines time zone information corresponding to the regionalinformation, produces a time correction instruction according to thetime zone information, and transmits the time correction instructionthrough the communication component to the other communication device.

According to a second aspect of this disclosure, an automatic timecorrection method uses a communication device that is provided in amobile body which is a means of transportation, and that is capable ofcommunicating with another communication device. The automatic timecorrection method includes, while the mobile body is traveling towardits destination, acquiring regional information indicating thedestination; determining zone information corresponding to the regionalinformation; producing a time correction instruction according to thetime zone information; transmitting the time correction instruction tothe other communication device; and correcting the time of the othercommunication device according to this time correction instruction.

The communication device, the communication system, and the automatictime correction method in this disclosure are effective at correctingtime information for a terminal used in a mobile body that is a means oftransportation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified diagram of an in-flight system;

FIG. 2 is a diagram of the simplified configuration of a base station;

FIG. 3 is a functional block diagram of the base station;

FIG. 4 is a diagram giving an example of a time conversion table 121;

FIG. 5 is a block diagram of the simplified configuration of a terminal;

FIG. 6 is a functional block diagram of the terminal;

FIG. 7 is a flowchart of the operation of the base station and terminal;

FIG. 8 is a diagram illustrating Embodiment 2;

FIG. 9 is a diagram illustrating Embodiment 2;

FIG. 10 is a diagram of the simplified configuration of a base station;

FIG. 11 is a functional block diagram of the base station;

FIG. 12 is a functional block diagram of the base station pertaining toa modification example;

FIG. 13 is a simplified diagram of an in-flight system;

FIG. 14 is a diagram of the simplified configuration of a base station;

FIG. 15 is a functional block diagram of a terminal;

FIG. 16 is a functional block diagram of the base station; and

FIG. 17 is a flowchart of the operation of the base station andterminal.

DETAILED DESCRIPTION

Embodiments will now be described in detail through reference to thedrawings. However, unnecessarily detailed description may be omitted insome cases. For instance, detailed description of already known facts orredundant description of components that are substantially the same maybe omitted. This is to avoid unnecessary repetition in the followingdescription, and facilitate an understanding on the part of a personskilled in the art. It will be apparent to those skilled in the art fromthis disclosure that the following descriptions of the embodiments areprovided for illustration only and not for the purpose of limiting theinvention as defined by the appended claims and their equivalents.

The inventor(s) has provided the appended drawings and the followingdescription so that a person skilled in the art might fully understandthis disclosure, but does not intend for these to limit what isdiscussed in the patent claims.

Embodiment 1

Embodiment 1 will now be described through reference to FIGS. 1 to 7.

1-1. Configuration

1-1-1. Configuration of In-Flight System 10

As shown in FIG. 1, in Embodiment 1, an aircraft 1 is used as an exampleof a mobile body, and the description will focus on a base station 100located in the aircraft 1, and a terminal 200 that can be wirelesslyconnected to the base station 100. As shown in FIG. 1, the aircraft 1comprises the in-flight system 10 (an example of a communicationsystem), which includes the base station 100 (an example of acommunication device), the terminal 200 (an example of anothercommunication device) that is wirelessly connected to the base station100, and a server 300 that is connected by cable or the like to the basestation 100.

The terminal 200 can correct time information on the basis ofinformation from the base station 100. In the depicted example, just oneterminal 200 is shown for the sake of easy-to-understand explanation,but actually the terminal 200 is owned by a passenger, and the basestation 100 can connect to a plurality of terminals 200.

When connection with the terminal 200 has been established, the basestation 100 individually instructs the terminal 200 to correct the timeset on the terminal. More specifically, the base station 100 sends eachterminal 200 connected to the base station 100 an IE (informationelement) defined by the NITZ (network identify and time zone). The IE ismade up of an IEI (information element indicator) that is one byte longand used for identifying information sent from the base station to theterminal, and an information portion that is uniquely set for every IEI.For instance, if the IEI is 46, the corresponding information portion isthe time difference in 15 minute increments from world standard time(that is, the local time zone (LTZ)). The time zone can also includeDaylight Saving Time, or adjustment for summer time, which will bediscussed below. If the IEI is 49, the corresponding information portionis a Daylight Saving Time adjustment of any of 0 hours, +1 hour, or +2hours. When the IEI is 47, the corresponding information portion isworld standard time and the time difference in 15 minute increments fromworld standard time (time zone). As discussed above, when the IE issent, the base station 100 issues a time correction instruction to theterminal 200.

1-1-2. Configuration of Base Station 100

The base station 100 is located in the aircraft 1, and transmits timecorrection instructions to the terminal 200 as discussed below. The timein the region where the base station 100 is used is different from thetime at the destination. That is, the base station 100 providesinformation about the time at the destination to the terminal 200 priorto reaching the destination.

The base station 100 functions as a base station for mobile phones, forexample, and executes communication with the terminal 200 in a mobilephone network configured along with the terminal 200, which is awireless communication device that conforms to standards such as 3GPP.

As shown in FIG. 2, the base station 100 is a communication device thatcomprises a transceiver 101, a controller 110 (an example of acontroller), a memory 120, a wireless communication component 105 (anexample of a communication component), and so forth, which are connectedto one another via a specific bus. The transceiver 101 is connected tothe server 300. The controller 110 includes a CPU or other processor,and executes a specific program. In particular, the controller 110executes the automatic time correction processing pertaining to thisembodiment by executing the function of a time zone determinationcomponent 111 and a time correction instruction production component 112(discussed below). The memory 120 stores various kinds of data, such asthe communication status of the device, and information about connectionto other communication devices. The memory 120 also holds a timeconversion table 121 (discussed below). The wireless communicationcomponent 105 is connected to a wireless antenna, and communicates withthe terminal 200.

FIG. 3 is a functional block diagram of the base station 100 pertainingto Embodiment 1.

The transceiver 101 receives destination information about the aircraft1 (an example of regional information) from the server 300. Thedestination information includes information specifying the destinationof the aircraft 1. The received destination information is output to thetime zone determination component 111.

The time zone determination component 111 refers to the time conversiontable 121 held in the memory 120 and determines the time zone for thereceived destination information.

As shown in FIG. 4, the time conversion table 121 holds time zones andDaylight Saving Time adjustments for each region. The time zonedetermination component 111 uses the time conversion table 121 todetermine the time zone and Daylight Saving Time adjustment of thedestination of the aircraft 1, with respect to the destinationinformation input from the transceiver 101. The time zone determinationcomponent 111 then outputs the time zone and Daylight Saving Timeadjustment for the destination of the aircraft 1 to the time correctioninstruction production component 112.

The time correction instruction production component 112 produces a timecorrection instruction defined by an NITZ (network identify and timezone), on the basis of the time zone and Daylight Saving Time adjustmentdetermined by the time zone determination component 111. That is, thetime correction instruction production component 112 produces the IEdefined by the NITZ, and outputs it as a time correction instruction tothe wireless communication component 105.

The wireless communication component 105 sends the time correctioninstruction input from the time correction instruction productioncomponent 112 to the connected terminal 200.

1-1-3. Configuration of Terminal

The terminal 200 is a smart phone, tablet terminal, laptop computer, orother such terminal carried by a passenger. As shown in FIG. 5, theterminal 200 comprises a controller 210, a memory 220, a displaycomponent 230, an input component 240, and a wireless communicationcomponent 250 that are connected via a specific bus, and runs softwarethat carries out various functions called applications with an operatingsystem such as Windows, Android, or iOS.

The controller 210 includes a CPU or other processor, and executes thevarious functions of the terminal 200 by executing a specific program.The controller 210 executes the function of a time correction component211 according to a time correction instruction received from the basestation 100. The memory 220 includes a standard time holder 221, andalso holds various other kinds of data. The display component 230 has anLCD, an organic EL display, or another such display screen, and displaysinformation corresponding to the instructions of the controller 210. Theinput component 240 is an input means such as a mouse, a keyboard,control buttons, or a touch panel displayed on the display component230, and is operated by the user to send the input information to thecontroller 210. The wireless communication component 250 sends andreceives commands, responses, and other such signals and data wirelesslyto and from the base station 100.

FIG. 6 is a functional block diagram of the terminal 200 pertaining toEmbodiment 1.

The wireless communication component 250 receives a time correctioninstruction from the base station 100.

The time correction component 211 decodes the time zone (includingDaylight Saving Time adjustment) included in the received timecorrection instruction, and acquires standard time information from thestandard time holder 221. The standard time is, for example, CoordinatedUniversal Time (UTC) (or it may be Greenwich Mean Time (GMT)). The timecorrection component 211 corrects the current time on the basis of theacquired time zone and standard time information, and outputs thecorrected time to the display component 230.

The display component 230 displays the corrected time produced by thetime correction component 211.

1-2. Operation

The operation of the base station 100 and the terminal 200 pertaining toEmbodiment 1 will be described in detail through reference to FIG. 7. Inthis embodiment, an example will be described in which the aircraft 1 isdeparting from Tokyo and will arrive in Los Angeles, as shown in FIG. 1.

First, the detailed operation of the base station 100 pertaining toEmbodiment 1 will be described.

Step S101: The controller 110 of the base station 100 acquiresdestination information (such as Los Angeles) for the aircraft 1 fromthe server 300. The reception of the destination information from theserver 300 may be accomplished by having the server 300 respond to arequest from the base station 100. Alternatively, the destinationinformation may be received ahead of time from the server 300, such aswhen the system is started up, and then read from the memory 120.

Step S102: The controller 110 (the time zone determination component111) refers to the memory 120, uses the time conversion table 121 forthe time zone and Daylight Saving Time adjustment for each region, andselects “UTC−8” (Universal Coordinated Time−8 hours) (or it may be GMT(Greenwich Mean Time)−8 hours) as the time zone corresponding to thedestination of Los Angeles.

Step S103: The controller 110 (the time zone determination component111) acquires the Daylight Saving Time adjustment corresponding to thedestination. In this embodiment, the Daylight Saving Time adjustmentcorresponding to the destination Los Angeles is “+1 hour.”

Step S104: The controller 110 (the time zone determination component111) totals up the time zone and the Daylight Saving Time adjustment tocalculate the time zone (including Daylight Saving Time adjustment)corresponding to the destination Los Angeles, which will be “UTC−7,” andsets this as the time zone. The time zone thus set may be stored in thememory 120.

Step S105: The controller 110 (the time correction instructionproduction component 112) produces a time correction instruction definedby NITZ on the basis of the time zone (including the Daylight SavingTime adjustment) of the destination determined by the time zonedetermination component 111. More specifically, the controller 110 (thetime correction instruction production component 112) produces as thetime correction instruction an IE including the time zone of thedestination (including the Daylight Saving Time adjustment), defined byIEI=46. That is, the base station 100 produces an instruction to correctto the time for the destination, which is different from that of theregion where the base station 100 is used (Tokyo in this example).

Step S106: The controller 110 sends the time correction instruction thusproduced through the wireless communication component 105 to theconnected terminal 200.

Here, the information the base station 100 sends to the terminal 200 isthe time zone of the destination (including the Daylight Saving Timeadjustment). Specifically, the base station 100 does not need to sendthe terminal 200 detailed time information, such as information aboutthe hours, minutes, and seconds of world standard time. Thus, few bitsof information need to be sent from the base station 100 to the terminal200. Also, since the time correction instruction is given individuallyto each terminal, the more terminals there are on the aircraft 1, thegreater the effect of lowering overhead related to communication will beas a result of reducing the number of bits. Furthermore, since there isno need to send detailed time information to the terminal 200, the basestation 100 does not have to hold detailed time information.Accordingly, the effect is that the configuration of the base station100 can be simplified.

In Embodiment 1, an example was given of moving between different timezones (from Tokyo to Los Angeles), but this is not the only option. Ifthe mobile body is moving between regions in which the time zone is thesame and only the Daylight Saving Time adjustment is different, the basestation 100 may produce as the time correction instruction an IEincluding the Daylight Saving Time adjustment of the destination,defined by IEI=49, and sent it to the terminal 200.

Also, in Embodiment 1, the time correction instruction was produced witha single IE (IEI=46) that combined the time zone and the Daylight SavingTime adjustment. Alternatively, separate time correction instructionsmay be produced: a time correction instruction with an IE including thetime zone defined by IEI=46 and a time correction instruction with an IEincluding a Daylight Saving Time adjustment defined by IEI=49. In thiscase, the time correction instructions are sent to the terminal 200, andadjustment for Daylight Saving Time is performed on the terminal 200side.

If the base station 100 has hour, minute, and second information aboutthe world standard time as detailed time information, an IE includingworld standard time and the time zone (and the Daylight Saving Timeadjustment) of the destination, defined by IEI=47, may be produced asthe time correction instruction and sent to the terminal 200.

Next, the detailed operation of the terminal 200 pertaining toEmbodiment 1 will be described. For the sake of description, it isassumed that a time based on the time zone “UTC+9” (such as Tokyo time)is being displayed at the point prior to reception of an instruction tocorrect the time to the time of the destination Los Angeles sent fromthe base station 100.

Step S107: The controller 210 of the terminal 200 carried in theaircraft 1 receives a time correction instruction sent out by the basestation 100.

Step S108: The controller 210 decodes the time zone information “UTC−7”acquired from the received time correction instruction.

Step S109: The controller 210 records the decoded time zone information“UTC−7” to the memory 220.

Step S110: The controller 210 changes the current time it is holding tothe time based on the time zone information “UTC−7,” and displays thenew time on the display component 230.

The terminal 200 may cancel the time zone information “UTC+9” frombefore the time correction, or in addition to displaying a time based on“UTC−7” as a first time, it may hold a time based on “UTC+9” as a secondtime and display both times on the display component 230.

1-3. Effects, Etc.

As discussed above, according to Embodiment 1, a time correctioninstruction including time zone information for the destination isproduced and sent from the base station 100 located in an aircraft.Accordingly, the user (a passenger) can automatically correct the timedisplayed on the terminal 200 to the time at the destination, withouthaving to register the departure time or reset the time that had beenset on the terminal 200 carried by the user.

Also, the base station 100 can automatically correct the time on theterminal 200 to the time at the destination while heading toward thedestination.

Also, the base station 100 does not need to send the terminal 200detailed time information for the destination (such as hour, minute, andsecond information about world standard time). Consequently, the numberof bits of data sent by the base station 100 to the terminal 200 can bereduced, which lowers the overhead related to communication.

Furthermore, the base station 100 does not need to send detailedinformation about the current time to the terminal 200, so detailed timeinformation does not have to be stored for time correction. Accordingly,the configuration and function of the base station 100 can besimplified.

Embodiment 2

Embodiment 2 will now be described through reference to FIGS. 8 to 12.

In this embodiment, if there is interference between the radio waves ofa base station 500 located in the aircraft 1 (mobile body) and the radiowaves of a ground base station 400 located near the departure sitebefore the aircraft 1 has taken off from the departure site (orimmediately after departure), correction of time information at theterminal 200 will still be carried out without any problem.

Those elements having the same configuration and function as inEmbodiment 1 will be numbered the same and referred to in the samedrawings, and will not be described again in detail.

FIGS. 8 and 9 show examples of the state of radio wave interference inthe aircraft 1 pertaining to Embodiment 2.

As shown in FIGS. 8 and 9, the ground base station 400 is located nearthe departure region of the aircraft 1. The ground base station 400 usesthe technology (NITZ) discussed in Non-Patent Literature 1 andNon-Patent Literature 2 and sends the time of the region where theground base station 400 is located (that is, the departure region) to aterminal 200 that is connected to the ground base station 400.

FIG. 8 shows how the ground base station 400 located near the departureregion and the base station 500 located in the aircraft 1 communicatewith the terminal 200 located in the aircraft 1 and a terminal 200 aoutside the aircraft 1, before the aircraft 1 has taken off from thedeparture site (or immediately after departure).

FIG. 9 shows how the ground base station 400 located near the departureregion and the base station 500 located in the aircraft 1 communicatewith the terminal 200 in the aircraft 1 and the terminal 200 a outsidethe aircraft 1, when the aircraft 1 is at a high altitude (such as analtitude of about 10,000 meters) after having taken off from thedeparture site.

As shown in FIG. 8, when the aircraft 1 is at a low altitude, such asbefore or immediately after departure, the terminal 200 in the aircraft1 is within the radio wave range of the ground base station 400 in thedeparture region, and receives a strong signal from the ground basestation 400. Accordingly, the terminal 200 in the aircraft 1 can receivesignals from the ground base station 400. Therefore, when the basestation 500 in the aircraft 1 sends out the time of the destinationregion at a low altitude, the terminal 200 in the aircraft 1 receivesthe time in the departure region from the ground base station 400, andalso receives the time at the destination from the base station 500 inthe aircraft 1.

At this point, it is possible that the times in the departure region andthe destination region will end up being corrected frequently. This sameproblem occurs at the terminal 200 a outside the aircraft and near thefuselage. Accordingly, if the base station 500 in the aircraft 1 sendsthe time for the destination region at a low altitude, the timedisplayed on the terminal 200 in the aircraft 1 and the terminal 200 aoutside the aircraft 1 will be switched frequently, which can beconfusing to the users of the terminals 200 and 200 a.

Meanwhile, as shown in FIG. 9, if the aircraft 1 is at a high altitude(such as an altitude of about 10,000 meters), the signal received by theterminal 200 in the aircraft 1 from the ground base station 400 will beweaker than the signal received from the base station 500 in theaircraft 1. The reason for this is that electromagnetic waves areattenuated in proportion to the distance they propagate from the groundbase station 400 to the terminal 200 in the aircraft 1, and that thedirectionality of the antenna of the ground base station 400 is facingthe ground. Accordingly, there is a lower probability that the terminal200 in the aircraft 1 will connect to the ground base station 400 atsuch a high altitude. Also, for the base station 500 in the aircraft 1to communicate with the terminal 200 in the aircraft 1, the base station500 in the aircraft 1 only has to output a signal that is strong enoughto cover the interior of the aircraft 1. Accordingly, there is also alower probability that the base station 500 in the aircraft 1 willaffect the terminal 200 a outside the aircraft 1.

In light of the above, in Embodiment 2, the base station 500 installedin the aircraft 1 only sends an instruction to correct to the time atthe destination to a terminal 200 carried in the aircraft 1 when theaircraft 1 has taken off and has reached a certain altitude (such as10,000 meters).

2-1. Configuration

As shown in FIG. 10, the base station 500 is a communication device thatcomprises a transceiver 501, a controller 510 (an example of acontroller), a memory 520, a wireless communication component 505 (anexample of a communication component), and so forth, which are connectedvia a specific bus. The controller 510 includes a CPU or otherprocessor, and executes a specific program. In particular, thecontroller 510 executes the automatic time correction processingpertaining to this embodiment by executing the function of a time zonedetermination component 511 and a time correction instruction productioncomponent 512, just as in Embodiment 1, and by executing the function ofa time correction instruction determination component 513. The memory520 stores various kinds of data, such as the communication status ofthe device, and information about connection to other communicationdevices. The memory 520 also holds a time conversion table 521, just asin Embodiment 1.

2-2. Operation

FIG. 11 is a functional block diagram of the base station 500 pertainingto Embodiment 2. As shown in FIG. 11, the base station 500 executes thefunctions of the transceiver 501, the time zone determination component511, the time correction instruction production component 512, thewireless communication component 505, and the time correctioninstruction determination component 513.

Just as in Embodiment 1, the transceiver 501 receives destinationinformation about the aircraft 1 from the server 300. The destinationinformation includes information specifying the destination of theaircraft 1. The received destination information is output to the timezone determination component 511. The transceiver 501 also receivesservice (flight) information for the aircraft 1 (such as cruisingaltitude information about the aircraft) from the server 300, andoutputs it to the time correction instruction determination component513.

Just as in Embodiment 1, for the received destination information, thetime zone determination component 511 refers to the time conversiontable 521 held in the memory 520, and outputs the time zone and DaylightSaving Time adjustment for the destination of the aircraft 1 to the timecorrection instruction production component 512.

Just as in Embodiment 1, the time correction instruction productioncomponent 512 produces an IE defined by the (NITZ), and outputs it as atime correction instruction to the wireless communication component 505.

Meanwhile, the time correction instruction determination component 513switches between transmission and non-transmission of the timecorrection instruction at the wireless communication component 505 onthe basis of the received service information (such as on the basis ofwhether or not the cruising altitude of the aircraft 1 has reached apredetermined altitude). That is, the wireless communication component505 sends a time correction instruction to the terminal 200 if the timecorrection instruction determination component 513 has determined thatthe cruising altitude of the aircraft 1 has exceeded a predeterminedaltitude (such as 10,000 meters), for example. On the other hand, thewireless communication component 505 does not send a time correctioninstruction if the time correction instruction determination component513 has determined that the cruising altitude of the aircraft 1 has notexceeded the predetermined altitude.

If no time correction instruction is sent, the produced correctioninstruction may be deleted, or it may be stored in the memory 520. Thebase station 500 sends the terminal 200 the time correction instructionread from the memory 520, or a correction instruction that has beenproduced again, when service information about the aircraft 1 isreceived from the server 300 again, and it has been determined that thecruising altitude of the aircraft 1 has reached a predeterminedaltitude.

2-3. Modification Example

2-3-1. Timing of Determination of Whether Time Correction InstructionCan Be Sent

The determination by the time correction instruction determinationcomponent 513 as to whether or not to send a time correction instructionmay be performed after destination information has been received by thetransceiver 501 from the server, and before the time zone is determinedby the time zone determination component 511. In this case, if the timecorrection instruction determination component 513 determines againsttransmission, the functions of the time zone determination component 511and the time correction instruction production component 512 are notexecuted.

2-3-2. Transmission of Time Correction Instruction

In this embodiment, before the aircraft 1 reaches a predeterminedaltitude, the base station 500 in the aircraft 1 does not send a timecorrection instruction to the terminal 200 in the aircraft 1. However,if the aircraft 1 is at a low altitude, such as before departure orimmediately after departure, a time correction instruction may be sentas long as it is the same as at the ground base station 400 in thedeparture region. Therefore, before the aircraft 1 reaches apredetermined altitude, the base station 500 in the aircraft 1 may “sendan instruction to correct to the time at the departure site” to theterminal 200 in the aircraft 1, instead of “not sending a timecorrection instruction.”

If “send an instruction to correct to the time at the departure site”applies, the same processing is performed as the processing to producean instruction to correct to the time at the destination. Detaileddescription on the processing will be given below.

Step 1: The controller 510 acquires departure site information (such asTokyo) from the server 300 via the transceiver 501, in addition todestination information for the aircraft 1.

Step 2: The controller 510 (the time zone determination component 511)refers to the memory 520, and uses the time conversion table 521 for thetime zone and Daylight Saving Time adjustment corresponding to eachregion to select “UTC+9” (Universal Coordinated Time+9 hours) as thetime zone corresponding to the departure site Tokyo.

Step 3: The controller 510 (the time zone determination component 511)acquires the Daylight Saving Time adjustment corresponding to thedeparture site. Here, it is assumed that the Daylight Saving Timeadjustment corresponding to the departure site Tokyo is “+0 hours.”

Step 4: The controller 510 (the time zone determination component 511)totals up the time zone and the Daylight Saving Time adjustment tocalculate the time zone (including Daylight Saving Time adjustment)corresponding to the departure site Tokyo, which will be “UTC+9,” andsets this as the time zone.

Step 5: The controller 510 (the time correction instruction productioncomponent 512) produces a time correction instruction defined by NITZ onthe basis of the time zone (including the Daylight Saving Timeadjustment) of the departure site determined by the time zonedetermination component 511.

Step 6: The controller 510 sends the time correction instruction thusproduced through the wireless communication component 505 to theconnected terminal 200.

2-3-3. Criteria for Determining Whether to Send Correction Instruction

The criterion used by the time correction instruction determinationcomponent 513 to determining whether to transmit is not limited to thecruising altitude of the aircraft 1.

After departure, the cruising altitude of the aircraft 1 is raised alongwith a cruising speed. At the same time, the aircraft moves away fromthe departure region. Accordingly, the timing at which the base station500 in the aircraft 1 sends a correction instruction to correct to thetime at the destination region may be (1) “after the aircraft hasreached a predetermined speed,” (2) “after the aircraft has flown apredetermined distance,” (3) “after a predetermined length of time haselapsed since the departure,” or (4) “after the aircraft has moved apredetermined distance away from the departure region,” instead of the“after the aircraft has reached a predetermined altitude” as in thisembodiment. Also, since the main issue is that the mobile phone networkdeveloped in the country of the departure region not be affected, thetiming for sending a correction instruction to correct to the time atthe destination region may also be (5) “after the aircraft has left acertain area (such as the territory, territorial waters, or airspace ofthe country where the departure region is),” or (6) “after the strengthof the signal received from a ground base station has dropped under apredetermined value,” instead of the “after the aircraft has reached apredetermined altitude.”

The above situations (1) to (6) will now be described.

In situation (1), the transceiver 501 receives cruising speedinformation as service information about the aircraft 1. In general, theaircraft 1 takes off at a speed of 250 to 300 km/h, and the aircraftlevels off at a speed of about 800 km/h. Accordingly, the base station500 installed in the aircraft 1 only sends a terminal 200 carried in theaircraft 1 an instruction to correct to the time of the destination whenthe aircraft 1 has taken off and has reached a predetermined speed (suchas a speed of 800 km/h).

In situation (2), the transceiver 501 receives cruising distanceinformation as service information about the aircraft 1. In general, theaircraft 1 rises at an angle of 3 to 7 degrees, and levels off at analtitude of 10,000 meters. For example, the cruising distance until analtitude of 10,000 meters is reached when the aircraft rises at an angleof 5 degrees is roughly 115 km (calculated as 10 km/sin(5)).Accordingly, the base station 500 installed in the aircraft 1 only sendsa terminal 200 carried in the aircraft 1 an instruction to correct tothe time of the destination when the aircraft 1 has taken off and hasflown a predetermined distance (such as 115 km).

In situation (3), the transceiver 501 receives cruising time informationas service information about the aircraft 1. For instance, if it takes20 minutes until the aircraft levels off, then the base station 500installed in the aircraft 1 only sends a terminal 200 carried in theaircraft 1 an instruction to correct to the time of the destination when20 minutes has elapsed since departure. Alternatively, departure timeinformation may be received as service information about the aircraft 1,in which case the base station 500 installed in the aircraft 1 onlysends a terminal 200 carried in the aircraft 1 an instruction to correctto the time of the destination when 20 minutes has elapsed since thedeparture time.

In situation (4), the transceiver 501 receives position information asservice information about the aircraft 1. Also, the base station 500holds position information about various airports. The base station 500may also receive position information about various airports from anexternal device. The base station 500 installed in the aircraft 1 onlysends a terminal 200 carried in the aircraft 1 an instruction to correctto the time of the destination when a predetermined radius has beenexceeded from the position of each airport.

In situation (5), the transceiver 501 receives position information asservice information about the aircraft 1. Also, the base station 500holds position information about a boundary at which switching controlis performed (such as the territorial waters of Japan). The base station500 may also receive position information about boundaries from anexternal device. The base station 500 installed in the aircraft 1 onlysends a terminal 200 carried in the aircraft 1 an instruction to correctto the time of the destination when a predetermined boundary has beencrossed.

In situation (6), an instruction to correct to the time of thedestination is sent according to the electric field strength from theground base station 400, that is, the received signal strength. Forexample, if the electric field strength is under a predetermined value,the base station 500 in the aircraft 1 sends the terminal 200 in theaircraft 1 an instruction to correct to the time of the destination.

The electric field strength may be measured directly by the base station500. In this case, as shown in FIG. 12, a base station 500′ is equippedwith an electric field strength measurement component 514, and themeasurement result is output to the time correction instructiondetermination component 513. The time correction instructiondetermination component 513 uses the measurement result to determinewhether or not a time correction instruction should be sent.

The electric field strength information may be received from an externaldevice, or it may be sent from the terminal 200 to the base station 500.

In the above situations (1) to (6), the time correction instructiondetermination component 513 of the base stations 500 and 500′ sends theterminal 200 an instruction to correct to the time of the destinationvia the wireless communication component 505 when a predeterminedthreshold has been exceeded.

After the predetermined threshold has been exceeded, if the value dropsback under the predetermined threshold, the time correction instructiondetermination component 513 may or may not send an instruction tocorrect to the time of the destination.

Also, the above situations (1) to (6) may allow the transmission of atime correction instruction if two or more conditions are met.

2-4. Effects, Etc.

As discussed above, in addition to the effect of Embodiment 1, theconfiguration according to

Embodiment 2 prevents such a problem that the time displayed on theterminal 200 in the aircraft 1 or on the terminal 200 a outside theaircraft 1 is switched frequently, which can confuse the users of theterminal 200 and the terminal 200 a.

Embodiment 3

Embodiment 3 will now be described through reference to FIGS. 13 to 17.

FIG. 13 is a diagram of the aircraft 1 that includes a base station 700pertaining to Embodiment 3.

In Embodiment 3, the aircraft 1 has at least one stopover site on theway to the final destination. The user of a first terminal 200A, whosedestination is a stopover site, and the user of a second terminal 200B,whose destination is the final destination of the aircraft 1, are bothon board the aircraft 1. The base station 700 corrects the time set onthe first terminal 200A to the time of the stopover site, and correctsthe time set on the second terminal 200B to the time of the finaldestination.

Those elements having the same configuration and function as inEmbodiment 1 will be numbered the same and referred to in the samedrawings, and will not be described again in detail. In the followingdescription, when there is no need to distinguish between the firstterminal 200A and the second terminal 200B, they will both be referredto as a terminal 200.

3-1. Configuration

As shown in FIG. 14, the base station 700 is a communication device thatcomprises a transceiver 701, a controller 710 (an example of acontroller), a memory 720, a wireless communication component 705 (anexample of a communication component), and so forth, which are connectedvia a specific bus. The transceiver 701 is connected to the server 300.The controller 710 includes a CPU or other processor, and executes aspecific program. In particular, the controller 710 executes anautomatic time correction processing pertaining to this embodiment byexecuting the function of a time zone determination component 711 and atime correction instruction production component 712, just as inEmbodiment 1, and by executing the function of a terminal determinationcomponent 715, which will be discussed below. The memory 720 storesvarious kinds of data, such as the communication status of the device,and information about connection to other communication devices, andalso holds a time conversion table 721, just as in Embodiment 1, as wellas destination information for each terminal (discussed below).

3-2. Operation

FIG. 15 is a functional block diagram of the terminal 200 in Embodiment3. FIG. 16 is a functional block diagram of the base station 700pertaining to Embodiment 3.

In FIG. 15, just as in Embodiment 1 shown in FIG. 5, the terminal 200has the controller 210, the memory 220, the display component 230, theinput component 240, and the wireless communication component 250. Inthis embodiment, the terminal 200 further includes a destinationinformation production component 212 whose function is executed by thecontroller 210. The operation of the destination information productioncomponent 212 will be discussed later.

In FIG. 16, the base station 700 has the transceiver 701, the terminaldetermination component 715, the time zone determination component 711,the time correction instruction production component 712, and thewireless communication component 705.

The operation of the terminal 200 and the base station 700 shown inFIGS. 15 and 16 will now be described through reference to FIG. 17.

Step S501: At the terminal 200, the user inputs destination information,and the input destination information is encoded by the destinationinformation production component 212.

Step S502: The wireless communication component 250 of the terminal 200sends the encoded destination information to the base station 700 in theaircraft.

Step S503: The transceiver 701 of the base station 700 receives thedestination information from the terminal 200.

Step S504: When the controller 710 (terminal determination component715) of the base station 700 receives destination information from theplurality of terminals 200A and 200B, each piece of destinationinformation is stored in the memory 720 so as to be associated with IDinformation for each terminal. For example, the destination informationcorresponding to the terminal 200A is stored as site A, which is astopover site, and the destination information corresponding to theterminal 200B is stored as site B, which is the final destination.

Steps S505 to S508: The time zone determination component 711 of thecontroller 710 determines the time zone for every terminal stored in thememory 720. Thereafter, a time correction instruction is produced by thesame process as in Embodiment 1 (steps S102 to S105 in FIG. 7) for everyterminal 200.

Step S509: The wireless communication component 705 sends thecorresponding terminal 200 the time correction instruction thusproduced.

Step S510: The wireless communication component 250 of the terminal 200Areceives an instruction to correct to the time corresponding to site A,which is a stopover site, from the base station 700, and the timecorrection component 211 of the controller 210 corrects the current timeto the time at site A, just as in Embodiment 1. Meanwhile, the wirelesscommunication component 250 of the terminal 200B receives an instructionto correct to the time corresponding to site B, which is thedestination, from the base station 700, and the time correctioncomponent 211 of the controller 210 corrects to the time at site B, justas in Embodiment 1.

In Embodiment 3, the destination information sent by the terminal 200 isnot limited to the destination of the aircraft 1, and may be the finaldestination of the user of the terminal 200. For example, there may be acase in which the user of the terminal 200B departs site S on theaircraft 1 in which the base station 700 is installed as shown in FIG.13, stops over in site A, and then arrives at site B on a differentaircraft from the aircraft 1. Here, the destination information sent bythe first terminal 200A will be site A, and the time correctioninstruction sent by the base station 700 to the first terminal 200A willbe an instruction to correct to the time A at site A. Meanwhile, thedestination information sent by the second terminal 200B will be site B,and the time correction instruction sent by the base station 700 to thesecond terminal 200B will be an instruction to correct to the time B atsite B.

3-3. Modification Example

The user carries and uses the terminal 200 in the aircraft 1 to senddestination information ahead of time to the base station 700, but thetransmission of destination information from the terminal 200 may bedone after connection to the base station 700 in the aircraft 1, or maybe done outside the aircraft 1, going from the server 300, through anetwork, to the base station 700.

Also, in Embodiment 3, the wireless communication component 705 receiveddestination information from the terminal 200, but this is not the onlyoption. For example, the base station 700 may store destinationinformation in the memory 720 ahead of time. In this case, for instance,destination information may come from reservation information (inaddition to destination information, it may include ID information aboutthe user (passenger), or ID information about the terminal 200) or thelike stored in the airline ticket reservation system operated by thecompany owning the aircraft 1, and may be sent through a network aheadof time to the base station 700. In this case, there is no need to senddestination information from the terminal 200 inside the aircraft 1.

Also, when destination information is sent from the terminal 200,boarding information (reservation number, airline ticket number, seatnumber, etc.) may be input instead of inputting destination information.In this case, when the boarding information is sent to the base station700, the base station 700 may acquire destination information on thebasis of reservation information and so forth acquired via the server300.

3-4. Effects, Etc.

As discussed above, with Embodiment 3, in addition to the effects ofEmbodiment 1, the base station 700 sends an instruction to correct tothe time corresponding to the destination, which varies for eachterminal 200. Consequently, the base station 700 can automaticallycorrect the time displayed on the terminal 200 of a user to the time atthe destination, which varies for each user. That is, regardless ofwhere the aircraft 1 is heading, the time of the terminal 200 can becorrected to the time of the destination of the user of that terminal200.

Other Embodiments

(1)

In the above embodiments, the wireless communication component of eachbase station communicated wirelessly via an antenna, but an antenna portcan similarly be used.

The term “antenna port” refers to a theoretical antenna made up of oneor more physical antennas. Specifically, “antenna port” may notnecessarily refer to one physical antenna, and may instead refer to anarray antenna made up of a plurality of antennas.

For instance, in LTE (long term evolution), how many physical antennasmake up an antenna port is not specified, and this is specified as theminimum unit at which a base station can send different referencesignals.

Also, an antenna port is sometimes specified as the minimum unit formultiplying the weighting of a precoding vector.

(2)

The functions of the base stations 100, 500, and 700 (and particularlythe controllers 110, 510, and 710) in the above embodiments may beprovided to the server 300 (an example of a communication device), whichis a computer device. In this case, the server 300 is a computer devicehaving the same configuration as that shown in FIGS. 2, 10, and 14(except for the wireless communication component), and its controllerdetermines the time zone (including Daylight Saving Time adjustment) andproduces instructions to correct to the destination time. The timecorrection instructions thus produced are sent from a transceiver,through a base station, to each terminal 200.

Also, the server 300 and the base stations 100, 500, and 700 may bedevices (an example of communication devices) that are integrated.

(3)

In the above embodiments, a system installed in the aircraft 1 was givenas an example, but this is not the only option. The above embodimentscan also be applied to any mobile body serving as a means oftransportation for the movement of people, such as automobiles andships.

(4)

In the above embodiments, the base station or server (communicationdevice) is not limited to being constituted solely by hardware, and canalso be realized by software in conjunction with hardware.

Also, the various functional blocks used in describing the aboveembodiments are typically in the form of integrated circuits. These maybe individually made into chips, or some or all of them may be includedon one chip. The concept of “integrated circuit” here is sometimesreferred to as an IC, system LSI, super LSI, or ultra LSI, depending onthe degree of integration.

The method for producing the integrated circuit is not limited to LSI,and may instead involve a dedicated circuit or a multipurpose processor.After LSI manufacture, an FPGA (field programmable gate array) thatallows programming, or a reconfigurable processor that allows thereconfiguration of settings or connection of circuit cells inside theintegrated circuits may be utilized.

Furthermore, if some technique for circuit integration should appearthat replaces LSI, either by the advance of semiconductor technology orby a separate technology derived from this, that technology may be usedto integrate the functional blocks. The application of biotechnology orthe like is also conceivable.

(5)

Some or all of the above embodiments may be combined. For instance, itis possible to combine Embodiment 2 with Embodiment 3.

(6)

The order in which the processing steps are executed in the aboveembodiments is not necessarily limited to what was discussed in theabove embodiments, and the execution order can be changed to the extentthat this does not depart from the gist of the invention.

(7)

The present invention is not limited to being a communication device orcommunication system in the above embodiments, and can instead be anautomatic time correction method.

(8)

As discussed above, embodiments were described as examples of thetechnology disclosed herein. The appended drawings and detaileddescription were provided to that end.

Therefore, the constituent elements illustrated in the appended drawingsand discussed in the detailed description can encompass not only thoseconstituent elements which are essential to solving the problem, butalso constituent elements that are not essential to solving the problem,and are given to illustrate the above-mentioned technology. Accordingly,just because these non-essential constituent elements are illustrated inthe appended drawings and discussed in the detailed description, itshould not be concluded that these non-essential constituent elementsare essential.

Also, the above embodiments were given to illustrate examples of thetechnology disclosed herein, so various modifications, substitutions,additions, omissions, and so forth can be made within the scope of theappended claims or equivalents thereof.

The present invention is useful in mobile communication systems and thelike.

General Interpretation of Terms

In understanding the scope of the present disclosure, the term“comprising” and its derivatives, as used herein, are intended to beopen ended terms that specify the presence of the stated features,elements, components, groups, integers, and/or steps, but do not excludethe presence of other unstated features, elements, components, groups,integers and/or steps. The foregoing also applies to words havingsimilar meanings such as the terms, “including”, “having” and theirderivatives. Also, the terms “part,” “section,” “portion,” “member” or“element” when used in the singular can have the dual meaning of asingle part or a plurality of parts. Also as used herein to describe theabove embodiment(s), the following directional terms “forward”,“rearward”, “above”, “downward”, “vertical”, “horizontal”, “below” and“transverse” as well as any other similar directional terms refer tothose directions of the communication device for mobile body,communication system for mobile body, and automatic time correctionmethod featuring communication device for mobile body. Accordingly,these terms, as utilized to describe the technology disclosed hereinshould be interpreted relative to the communication device for mobilebody, communication system for mobile body, and automatic timecorrection method featuring communication device for mobile body.

The term “configured” as used herein to describe a component, section,or part of a device includes hardware and/or software that isconstructed and/or programmed to carry out the desired function.

The terms of degree such as “substantially”, “about” and “approximately”as used herein mean a reasonable amount of deviation of the modifiedterm such that the end result is not significantly changed.

While only selected embodiments have been chosen to illustrate thepresent invention, it will be apparent to those skilled in the art fromthis disclosure that various changes and modifications can be madeherein without departing from the scope of the invention as defined inthe appended claims. For example, the size, shape, location ororientation of the various components can be changed as needed and/ordesired. Components that are shown directly connected or contacting eachother can have intermediate structures disposed between them. Thefunctions of one element can be performed by two, and vice versa. Thestructures and functions of one embodiment can be adopted in anotherembodiment. It is not necessary for all advantages to be present in aparticular embodiment at the same time. Every feature which is uniquefrom the prior art, alone or in combination with other features, alsoshould be considered a separate description of further inventions by theapplicants, including the structural and/or functional concepts embodiedby such feature(s). Thus, the foregoing descriptions of the embodimentsaccording to the present invention are provided for illustration only,and not for the purpose of limiting the invention as defined by theappended claims and their equivalents.

What is claimed:
 1. A communication device provided in a mobile bodywhich is a means of transportation, the communication device beingconfigured to communicate with one other communication device, saidcommunication device comprising: a communication component configured toconnect to the one other communication device; and a controllerconfigured to control the communication component, the controller beingconfigured to: acquire regional information indicating at least adestination of the mobile body; determine time zone informationcorresponding to the regional information; produce a time correctioninstruction according to the time zone information; and transmit thetime correction instruction through the communication component to theone other communication device.
 2. The communication device according toclaim 1, wherein the controller is further configured to: acquireservice information for the mobile body; and determine whether or notthe time correction instruction can be transmitted according to theservice information, and the communication component is configured toswitch between transmission and non-transmission of the time correctioninstruction according to the determination of the controller.
 3. Thecommunication device according to claim 2, wherein the mobile body is anaircraft, the service information includes cruising altitude informationfor the aircraft, and the controller is configured to: determine whetheror not a cruising altitude acquired from the cruising altitudeinformation exceeds a predetermined value; and transmit the timecorrection instruction through the communication component to the oneother communication device if the cruising altitude has exceeded thepredetermined value.
 4. The communication device according to claim 2,wherein the mobile body is an aircraft, the service information includescruising speed information for the aircraft, and the controller isconfigured to: determine whether or not a cruising speed acquired fromthe cruising speed information exceeds a predetermined value; andtransmit the time correction instruction through the communicationcomponent to the one other communication device if the cruising speedhas exceeded the predetermined value.
 5. The communication deviceaccording to claim 2, wherein the service information includes traveldistance information for the mobile body, and the controller isconfigured to: determine whether or not a travel distance acquired fromthe travel distance information exceeds a predetermined value; andtransmit the time correction instruction through the communicationcomponent to the one other communication device if the travel distancehas exceeded the predetermined value.
 6. The communication deviceaccording to claim 2, wherein the service information includes departuretime information for the mobile body, and the controller is configuredto: determine whether or not a predetermined length of time has elapsedsince a departure time acquired from the departure time information; andtransmit the time correction instruction through the communicationcomponent to the one other communication device if the predeterminedlength of time has elapsed since the departure time.
 7. Thecommunication device according to claim 2, wherein the serviceinformation includes travel time information for the mobile body, andthe controller is configured to: determine whether or not a travel timeacquired from the travel time information has reached a predeterminedlength of time; and transmit the time correction instruction through thecommunication component to the one other communication device if thepredetermined length of time has been reached.
 8. The communicationdevice according to claim 2, holding information indicating a positionof a departure site of the mobile body, wherein the service informationincludes information for a position where the mobile body is, and thecontroller is configured to: determine whether or not the mobile bodyhas traveled at least a predetermined distance from the departure site;and transmit the time correction instruction to the one othercommunication device if the mobile body has traveled at least thepredetermined distance from the departure site.
 9. The communicationdevice according to claim 2, holding predetermined zone information,wherein the service information includes information for a positionwhere the mobile body is, and the controller is configured to: determinewhether or not the mobile body has gone beyond a predetermined zoneacquired from the predetermined zone information; and transmit the timecorrection instruction to the one other communication device if themobile body has gone beyond the predetermined zone.
 10. Thecommunication device according to claim 1, further comprising anelectric field strength measurement component configured to measure anelectric field strength from a ground base station, wherein thecontroller is configured to: determine whether or not the electric fieldstrength is at or below a predetermined value; and transmit the timecorrection instruction to the one other communication device if theelectric field strength is at or below the predetermined value.
 11. Thecommunication device according to claim 1, wherein the controller isfurther configured to: acquire service information for the mobile bodyand information indicating a departure site of the mobile body as theregional information; determine on the basis of the service informationwhether or not the time correction instruction is to be transmitted;determine second time zone information corresponding to the regionalinformation indicating the departure site if the controller hasdetermined the time correction instruction is not to be transmitted;produce a second time correction instruction according to the secondtime zone information; and transmit the second time correctioninstruction through the communication component to the one othercommunication device.
 12. The communication device according to claim 1,wherein the communication component is configured to connect to aplurality of other communication devices, and the controller isconfigured to: acquire first regional information indicating adestination of a user of a first other communication device and a secondregional information indicating a destination of a user of a secondother communication device, among the plurality of other communicationdevices; determine first time zone information corresponding to thefirst regional information, and second time zone informationcorresponding to the second regional information; produce a first timecorrection instruction according to the first time zone information, anda second time correction instruction according to the second time zoneinformation; transmit the first time correction instruction through thecommunication component to the first other communication device; andtransmit the second time correction instruction through thecommunication component to the second other communication device. 13.The communication device according to claim 1, wherein the controller isconfigured to produce the time correction instruction and transmits thetime correction instruction through the communication component to theone other communication device while the mobile body is traveling towardthe destination.
 14. A communication system, comprising: thecommunication device according to claim 1; and one other communicationdevice configured to communicate with the communication device accordingto claim 1, the one other communication device being configured toreceive the time correction instruction and correct a time of the oneother communication device according to the received time correctioninstruction.
 15. An automatic time correction method using acommunication device provided in a mobile body which is a means oftransportation, the communication device being configured to communicatewith one other communication device, said communication methodincluding: while the mobile body is traveling toward a destination ofthe mobile body, acquiring regional information indicating thedestination; determining time zone information corresponding to theregional information; producing a time correction instruction accordingto the time zone information; transmitting the time correctioninstruction to the one other communication device; and correcting a timeof the one other communication device according to the time correctioninstruction.